GRASS GIS fails to start without terminal

[wenzeslaus]

On Ubuntu (16.04):

• Do Ctrl+F2 (window to directly run commands - rather than desktop applications)
• Type grass
• Fill the startup screen
• Start session
• Start fails

In 7.2 you get error about g.extension (#3253) and trunk you don't get anything (it fails later on).

It is reproducible with nohup:

nohup grass

Using less nohup.out you can get the output which mainly reveals:

ERROR: Variable 'LOCATION_NAME' not set

followed by

Traceback (most recent call last):
  File "/usr/lib/grass72/gui/wxpython/wxgui.py", line 158, in <module>
    sys.exit(main())
  File "/usr/lib/grass72/gui/wxpython/wxgui.py", line 145, in main
    app = GMApp(workspaceFile)
  File "/usr/lib/grass72/gui/wxpython/wxgui.py", line 48, in __init__
...
grass.exceptions.CalledModuleError: [it depends]
Traceback (most recent call last):
  File "/usr/lib/python2.7/atexit.py", line 24, in _run_exitfuncs
    func(*targs, **kargs)
PyAssertionError: C++ assertion "GetEventHandler() == this" failed at ../src/common/wincmn.cpp(478) in ~wxWindowBase(): any pushed event handlers must have been removed
Error in sys.exitfunc:
Traceback (most recent call last):
  File "/usr/lib/python2.7/atexit.py", line 24, in _run_exitfuncs
    func(*targs, **kargs)
wx._core.PyAssertionError: C++ assertion "GetEventHandler() == this" failed at ../src/common/wincmn.cpp(478) in ~wxWindowBase(): any pushed event handlers must have been removed

Workaround which assumes you have some default mapset already:

grass --exec g.gui

Answer to the "What did you expect to happen?" question:

• GRASS GIS should start using this method as other applications do (e.g. QGIS or Gimp).

Other possible improvements:

• Message saying that the session is not started instead of "Variable 'LOCATION_NAME' not set"
• Some temporary location generated for the case where there is not 'last location used' so that grass --exec g.gui (or grass --tmp-loc --exec g.gui) works on a fresh machine (it seems that the demolocation is not part of the Ubuntu distribution)
• The above point and code packed into just grass. This comes to the discussion about role of location at startup from different side. However, it is pretty far from the core of this ticket which deals with GRASS GIS running without terminal.

[wenzeslaus]

From the nohup case I get the following in the output (as expected, I suppose):

/bin/bash: error reading input file: Bad file descriptor
WARNING: Failed to start shell '/bin/bash'

With the following patch, nohup case actually runs.

grass.py

@@ -1386 +1386 @@
     
     # Check for gui interface
     if grass_gui == "wxpython":
-        Popen([os.getenv('GRASS_PYTHON'), wxpath("wxgui.py")])
+        return Popen([os.getenv('GRASS_PYTHON'), wxpath("wxgui.py")])
+    return None
 
 
 def close_gui():
@@ -1961 +1962 @@
                                             mapset_settings.location)
 
         # start GUI and register shell PID in rc file
-        start_gui(grass_gui)
+        gui_process = start_gui(grass_gui)
         kv = read_gisrc(gisrc)
         kv['PID'] = str(shell_process.pid)
         write_gisrc(kv, gisrc)
@@ -1968 +1969 @@
         exit_val = shell_process.wait()
         if exit_val != 0:
             warning(_("Failed to start shell '%s'") % os.getenv('SHELL'))
+            # remove shell PID because GUI should not kill it
+            kv = read_gisrc(gisrc)
+            del kv['PID']
+            write_gisrc(kv, gisrc)
+            # if there is no shell but GUI is set, wait for that
+            if grass_gui != "text":
+                gui_process.wait()
 
         # close GUI if running
         close_gui()

However, with Ctrl+F2 I still get the same behavior. I don't see anything helpful in the sudo strace -p... -s9999 -e write output (using PID of grass and gis_set.py).

[neteler]

Ticket retargeted after milestone closed

[wenzeslaus]

Both cases, Ctrl+F2 and nohup, fixed by ​PR:768. Open new issues on GitHub in case there are follow up problems.